Casing assembly, battery cell, battery, and electric apparatus

A casing assembly applied to a battery cell, the casing assembly comprising:

• a casing, wherein the casing is provided with a through hole;
• and
• a sealing assembly, wherein the sealing assembly is configured to seal the through hole, and the sealing assembly comprises a conductive member, an insulating member, and a connecting member;
• wherein
• the insulating member covers the conductive member, and the conductive member has a first contact portion and a second contact portion respectively exposed from the insulating member;
• the connecting member is of an annular shape and has a first end surface and a second end surface, the first end surface is configured to face towards an exterior of the casing, the second end surface is configured to face towards an interior of the casing, and the insulating member covers at least a portion of the first end surface and at least a portion of the second end surface;
• and
• the connecting member is formed with a hollow inner cavity between the first end surface and the second end surface, at least a part of the insulating member fills the inner cavity, the connecting member is configured to be connected to the casing, and the first contact portion and the second contact portion are respectively located at an inner side and an outer side of the casing.